Rename the program to sww and its deciding daemon to discriminator

The program is now sww, built from cmd/sww, with two modes: sww rproxy and
sww discriminator. servewaf becomes discriminator everywhere it names that
daemon: the package (internal/discriminator), its types, functions, files, the
discriminator_line log field, and its docs and tests.

smallwebwaf is left only where sneak's directive allows it: the documents'
product name, the git.eeqj.de/sneak/smallwebwaf URLs, and the Go module path
sneak.berlin/go/smallwebwaf. Everywhere else a name containing it takes the sww
form: the package (internal/sww), metric names (sww_*), the X-Sww-* headers,
the /_sww/ admin endpoints, the SWW_COMMAND setting, the OS user, and the state
and rules directories.

No logic changes. make check passes.

Model: deepseek-v4-pro

internal/state/state.go

@@ -1,4 +1,4 @@
-// Package state keeps smallwebwaf's state in JSON files in
+// Package state keeps sww's state in JSON files in
 // SWWAF_STATE_DIR, as the "Persistent state" section of SPEC.md requires
 // and docs/state-files.md lists them:
 // bans.json holds the bans, clients.json each client's counters and
@@ -8,7 +8,7 @@
 // cooldowns, the hour under way, the alerts waiting for each destination
 // and the anomaly counters. Load
 // reads them at start, Watch takes in an admin's edit of one while
-// smallwebwaf runs, and Run and WriteAll write them. The disk is read and
+// sww runs, and Run and WriteAll write them. The disk is read and
 // written outside the parts' locks, which are held only to take a
 // snapshot or to put in what a file holds, so that no request waits on
 // the disk.
@@ -44,7 +44,7 @@ import (
 // version is the version of the files' format, the only one read.
 const version = 1
 
-// fileMode lets the smallwebwaf user alone read and write the files, which
+// fileMode lets the sww user alone read and write the files, which
 // hold visitors' addresses.
 const fileMode = 0o600
 
@@ -81,7 +81,7 @@ type Params struct {
 	CounterInterval time.Duration
 	// Ledger, Limiter, GeoJS, Lists, DNSBL, AbuseIPDB, Alerts and Anomalies
 	// hold the state. Alerts also receive a file_error alert for an edit set
-	// aside, and for a write that fails while smallwebwaf runs.
+	// aside, and for a write that fails while sww runs.
 	Ledger    *bans.Ledger
 	Limiter   *ratelimit.Limiter
 	GeoJS     *lookup.GeoJS
@@ -101,7 +101,7 @@ type Params struct {
 	Metrics *metrics.Metrics
 }
 
-// Files are the state files of a running smallwebwaf.
+// Files are the state files of a running sww.
 type Files struct {
 	params Params
 
@@ -110,7 +110,7 @@ type Files struct {
 	// it.
 	mu sync.Mutex
 	// sums are the SHA-256 sums of what each file held, by name, when
-	// smallwebwaf last read or wrote it. A file that holds anything else
+	// sww last read or wrote it. A file that holds anything else
 	// has been edited since.
 	sums map[string][sha256.Size]byte
 }
@@ -241,7 +241,7 @@ func (f *Files) Run(ctx context.Context) {
 	}
 }
 
-// WriteAll writes every state file, as smallwebwaf stops. A file that
+// WriteAll writes every state file, as sww stops. A file that
 // fails does not keep the others from being written.
 func (f *Files) WriteAll() error {
 	return errors.Join(f.writeFile(bansJSON), f.writeFile(clientsJSON),
@@ -250,7 +250,7 @@ func (f *Files) WriteAll() error {
 
 // Watch watches Dir until ctx is done, and takes in an admin's edit of a
 // state file as soon as it is saved: what the file holds replaces what
-// smallwebwaf held for it. An edit that does not parse is left for the
+// sww held for it. An edit that does not parse is left for the
 // file's next write, which sets it aside, since a file can be read while
 // an editor is still writing it. If Dir cannot be watched, that is
 // logged, and an edit is taken in only before its file is written.
@@ -310,7 +310,7 @@ func (f *Files) logFailure(name string, err error) {
 }
 
 // fileChanged takes in what the state file name holds, as Watch sees it
-// change, if that is an edit made since smallwebwaf last read or wrote
+// change, if that is an edit made since sww last read or wrote
 // the file. A file that cannot be read or does not parse is left for its
 // next write.
 func (f *Files) fileChanged(name string) {
@@ -326,7 +326,7 @@ func (f *Files) fileChanged(name string) {
 }
 
 // takeInEdit takes in data, an edit of the state file name, as takeIn
-// does, and counts and logs it. Every edit taken in while smallwebwaf
+// does, and counts and logs it. Every edit taken in while sww
 // runs, by Watch or by a write, is taken in here. An edit that does not
 // parse is neither counted nor logged, and takeIn's error returned.
 func (f *Files) takeInEdit(name string, data []byte) error {
@@ -356,8 +356,8 @@ func (f *Files) read(name string) (int, error) {
 }
 
 // readChanged returns what the state file name holds, and whether that
-// has changed since smallwebwaf last read or wrote the file, as it has
-// for a file smallwebwaf never read or wrote. A missing file has not
+// has changed since sww last read or wrote the file, as it has
+// for a file sww never read or wrote. A missing file has not
 // changed: it is written again at its next write.
 func (f *Files) readChanged(name string) ([]byte, bool, error) {
 	path := filepath.Join(f.params.Dir, name)
@@ -377,7 +377,7 @@ func (f *Files) readChanged(name string) ([]byte, bool, error) {
 // takeIn parses data, what the state file name holds, puts it into the
 // part that keeps that state, in place of what the part held, and returns
 // how many entries the file holds. edit is whether data is an admin's
-// edit taken in while smallwebwaf runs, rather than the file read at the
+// edit taken in while sww runs, rather than the file read at the
 // start. An error names the file and, where the JSON decoder tells it,
 // the line and column, or else the entry.
 func (f *Files) takeIn(name string, data []byte, edit bool) (int, error) {
@@ -491,8 +491,8 @@ func (f *Files) takeInAlerts(path string, data []byte) (int, error) {
 	return entries, nil
 }
 
-// writeFile writes the state file name from what smallwebwaf holds. An
-// edit made since smallwebwaf last read or wrote the file is taken in
+// writeFile writes the state file name from what sww holds. An
+// edit made since sww last read or wrote the file is taken in
 // first, so that it is not overwritten, or set aside if it does not
 // parse. A file that cannot be read, or an edit that cannot be set
 // aside, is left as it is, and the write given up. Every write is counted
@@ -561,7 +561,7 @@ func (f *Files) setAside(name string, parseErr error) error {
 	return nil
 }
 
-// encode returns the state file name as smallwebwaf writes it, from a
+// encode returns the state file name as sww writes it, from a
 // snapshot of the part that keeps that state.
 func (f *Files) encode(name string) ([]byte, error) {
 	switch name {
@@ -965,7 +965,7 @@ func parse(path string, data []byte, file stateFile) error {
 
 	err := json.Unmarshal(data, &header)
 	if err == nil && header.Version != version {
-		err = fmt.Errorf("%w %d, where this smallwebwaf reads version %d",
+		err = fmt.Errorf("%w %d, where this sww reads version %d",
 			errVersion, header.Version, version)
 	}